1. Field of the Invention
The present invention relates to drive shaft assemblies for a wheeled motor vehicle, and more particularly, to drive shaft assemblies of a type which are constructed to assure a balanced rotation thereof for minimizing undesired vibration of the motor vehicle in which the drive shaft assembly is used.
2. Description of the Prior Art
Hitherto, various types of automotive drive shaft assemblies have been proposed and put into practical use, some of which are disclosed in "AUTOMOTIVE ENGINEERING HANDBOOK" (issued June 1987 from Shadan Hohjin Jidousha Gijutukai).
In order to clarify the task of the present invention, one conventional drive shaft assembly for a wheeled motor vehicle will be described with reference to FIG. 13.
The drive shaft assembly 100 shown in the drawing is of a double joint type, which comprises a shaft proper 200 whose one end is connected through a joint unit 300 to an output shaft (not shown) of a power plant which includes an engine and a transmission. The other end of the shaft proper 200 is connected through another joint unit 400 to an input shaft (not shown) of a terminal speed reduction gear. Accordingly, the power produced by the engine is transferred through the drive shaft assembly 100 to the terminal reduction gear and then to driven road wheels (not shown).
Designated by numeral 500 is a balance weight which is secured to a certain portion of the shaft proper 200 to reduce vibrations of the shaft proper 200 during rotation of the same. The portion to which the balance weight 500 must be fixed is detected with the aid of special equipment.
However, as is described hereinabove, the abovementioned conventional drive shaft assembly requires troublesome and skilled work for restoring, the balance of the same. This causes an increase in production cost of the drive shaft assembly. Furthermore, such a balance restoring method has a certain inevitable limitation in reducing the vibrations of the assembly.